The present invention relates generally to a conversation support system and a conversation support method for supporting a virtual conversational environment in which a plurality of users can participate, the system and the method being built and provided on a computer network such as the Internet. More especially, the present invention relates to a conversation support system and a conversation support method for supporting a virtual conversational environment in which a plurality of users can participate in a virtual world having a predetermined spatial expanse built on a computer network.
To be more specific, the present invention relates to a conversation support system and a conversation support method for allowing users to communicate with each other without actually meeting each other in a shared virtual world having a spatial expanse built on a computer network and, more particularly, to a conversation support system and a conversation support method for allowing users to communicate with each other in virtual worlds beyond the framework of a single shared virtual world.
Recently, remarkable advances in computing technologies in information processing and information communication have been made and, on the basis thereof, computer systems have become widespread. Also, demands for network computing technologies for interconnecting computers have been growing. On networks, users of computers can smoothly share computer resources and share, distribute and exchange information. In addition, computer users can carry out collaborative work on their computers interconnected by networks.
Computers are interconnected by various types of networks. For example, these networks include LANs (Local Area Networks) such as Ethernet and Bluetooth, a WAN (Wide Area Network) formed by interconnecting LANs by leased lines for example, and the Internet which has grown to a worldwide network as a result of repeatedly interconnecting smaller networks.
The Internet is a network which has evolved from the ARPANET (Advanced Research Projects Agency Network) built by the U.S. Department of Defense. From the ARPANET, the Internet was then included in NSFNET (National Science Foundation Network) of U.S. National Science Foundation. Further, with the backbone of NSFNET transferred to nongovernment organizations in 1995, the fully fledged expansion known today of the Internet started. The Internet has grown to the today's gigantic network as a result of the repetition of autonomous interconnections of servers (mainly UNIX workstations) installed in universities and research organizations. The servers on the Internet are interconnected normally on the basis of TCP/IP (Transmission Control Protocol/Internet Protocol). Currently, millions of servers are connected to the Internet, each server making public its various resource objects to countless clients.
On the Internet, many services such as the WWW (World Wide Web), News, TELNET (TELetypewriter NETwork), FTP (File Transfer Protocol), and Gopher for example are provided for the general public. Of these services, WWW is a worldwide information search system providing an information space having a hyperlink structure and the main factor for the explosive growth and fast popularization of the Internet.
The WWW, invented by Tim Bernes-Lee at CERN (European Center for Nuclear Research) of Switzerland, is a worldwide information search system that allows accessing various media such as text, image, and voice in the form of hypertext. The hypertext information handled on the WWW is described in a hypertext description language called HTML (Hyper Text Markup Language). According to HTML-based hypertext description, the logical structure of document can be expressed by formatting delimited basically by “<” and “>”. A protocol used for transferring HTML files on TCP/IP networks is called HTTP (Hyper Text Transfer Protocol).
Currently, countless number of HTML documents, namely information resources, are presented with and without charge on the Internet. According to TCP/IP, various information resources including these HTML documents are identified by identifiers having a format called URL (Uniform Resource Locators). A URL is character string specifying means for accessing an information resource and the name thereof and described in the form of “scheme name (protocol name)://host name (domain name): port number/pass number (file name)”. An HTML document can include a link relationship with another information source, the link information also being specified in the form of URL.
The WWW is a system constructed in a client-server model. A WWW server is a computer system that operates server software called an HTTP daemon and stores and/or provides information resources described in HTML form (the daemon generically denotes programs that execute system management and processing in the background in UNIX environment).
A WWW client is a computer which operates by use of a user agent called a WWW browser or an HTML browser. Typical WWW browsers are “Netscape Navigator” of Netscape Communications and “Internet Explorer” of Microsoft Corp.
A WWW client user can specify desired information resources by entering a URL character string into a location box on a WWW browser screen. Normally, a WWW browser accesses or retrieves information resources on WWW servers in accordance with HTTP (Hyper Text Transfer Protocol). Besides, a WWW browser analyzes a retrieved HTML document and displays its contents on the browser window screen (namely, a home page is constructed on the browser screen). On a WWW page displayed on the browser screen, link information is indicated as “anchor”. The user clicks this anchor can specify an information resource of next reference destination. That is, via a WWW browser screen, the user searches a WWW information resource space in which hyper links are woven on the Internet to sequentially access various desired information resources.
In addition to the WWW, various applications such as BBS (Bulletin Board System) and chatting are available on the Internet.
A BBS is a system by which computerized bulletin information is accumulated on a server on a network and the accumulated information is made available for the viewing by users through the network. A BBS allows the centralized management of information on a server and the realtime exchanging of information between remotely distributed users.
Chatting is an online talking system which allows realtime conversation between users through keyboard inputted words via a network. Normally, two or more users log in a chat for a simultaneous talk in which remarks made by one user are displayed on the monitor screens of all users. Chatting allows remotely distributed users to make realtime conversation and discussion in a virtual world constructed on the Internet. Only logging in a virtual world provided by a chatting system instantly qualifies users to join a chat session. Besides, the users participating in a chat session need not be known by sight in the real world. These are major advantages of chatting. While the interaction by BBS is asynchronous, the conversation by chat is synchronous and therefore each participant can make remarks while checking the reactions of chatting mates, which makes the communication livelier than BBS.
For example, a cyberspace service named Habitat (trademark) is known in the so-called personal computer communications services. Development of Habitat started in 1985 by Lucas Film of the US, operated by Quantum Link, one of US commercial networks, for about three years. Then, Habitat started its service in NIFTY-Serve as Fujitsu Habitat (trademark) in February 1990.
In Habitat, users can send their alter egos called avatars (the incarnation of a god figuring in the Hindu mythology) into a virtual city called Populopolis drawn by two-dimensional graphics to have a chat (namely, a realtime conversation based on text entered and displayed) with each other. For further details of Habitat, refer to the Japanese translation of “Cyberspace: First Steps,” Michael Benedikt, ed., 1991, MIT Press Cambridge, Mass., ISBN0-262-02327-X, the translation being published Mar. 20, 1994, by NTT Publishing, ISBN4-87188-265-9C0010, pp. 282–307.
Meanwhile, the information resources handled on the Internet were initially nothing but two-dimensional, flat representations. For example, the HTML documents handled on the WWW system only describe two-dimensional information. Therefore, the HTML content displayed on an HTML browser screen, or a home page screen, is nothing but two-dimensional, flat representation.
In the conventional cyberspace systems operated by personal computer communications services such as mentioned above, a virtual reality street and the inside of a room for example are drawn in two-dimensional graphics. Therefore, moving an avatar in the depth direction is realized simply by moving it up and down in the background of the two-dimensional graphics. This results in a poor expression in simulating walking and movement in a virtual reality space. Also, the two-dimensional virtual reality space in which own avatar and the avatar of another user are displayed is viewed from a viewpoint of a third party, thereby impairing the sense of simulated experience.
On the other hand, VRML (Virtual Reality Modeling Language) was developed as a language to enable the description of three-dimensional information and the setting of hypertext links for objects drawn by three-dimensional graphics by extending the WWW. VRML allows to handle the appearance (for example, a lighting condition) and geometry of a three-dimensional object as data. In addition, VRML can assign a name to an object to describe the action of the name in a Java programming language.
VRML 1.0 allows mainly the still object representations in which a three-dimensional object changes in response to a mouse operation by the user. VRML 2.0, for which the specifications based on “moving world” were made public, adds three-dimensional object autonomous behavior, animation mapping, audio data handling, interactive representations for example. Details of VRML are disclosed in the Japanese translation of “VRML: Browsing & Building Cyberspace,” Mark Pesce, 1995, New Readers Publishing, ISBN1-56205-498-8, the translation being entitled “Getting to Know VRML: Building and Browsing Three-Dimensional Cyberspace,” translated by Kouichi Matsuda, Teruhisa Kamachi, Akikazu Takeuchi, Yasuaki Honda, Junichi Rekimoto, Masayuki Ishikawa, Ken Miyashita and Kazuhiro Hara, published Mar. 25, 1996, Prentice Hall, ISBN4-931356-37-0 for example.
The official and complete specifications of VRML 2.0 are publicized at “http://webspace.sgi.com/moving-worlds/spec/index.html” and the Japanese version thereof is publicized at “http://www.webcity.co.jp/info/andoh/VRML/vrm12.0/spec-jp/index.html.”
Construction of a three-dimensional virtual space by use of VRML 2.0 requires to only create a VRML file as follows:
(1) create graphic data indicative of the geometry, motion, and position of an object (or a model) in the virtual space (this process is called modeling);
(2) add a switch (or a sensor) to the model for generating an event in response to a mouse operation by user in which the user clicks the model in the displayed virtual space (this process is called sensor addition);
(3) program a script for realizing an event in response to the operation by user on the sensor (this processing is called scripting); and
(4) relate sensor operation with script activation and graphic data with the script (this processing is called routing).
VRML content can be accessed by use of a VRML browser. Namely, desired VRML content can be read from a WWW resource space on the Internet to be displayed through a VRML browser. The user can roam about in the displayed three-dimensional space by use of a pointing device such as a mouse. As the user moves in the displayed three-dimensional space, the displayed screen changes realtime to a scene viewed from each moving position. Movement in a narrow range is displayed by re-computing the three-dimensional data on the client side. A hypertext link may be set to an object (for example, a cuboid or a column) drawn by use of three-dimensional graphics. Namely, the user can search a three-dimensionally displayed screen with a mouse cursor to reach another item of VRML content or HTML content by clicking an anchor displayed represented in a three-dimensional object.
For example, VRML allows the description of a three-dimensional shared virtual space to be shared by two or more users. The above-mentioned chatting was initially a system by which words inputted by participants through their keyboards are only sequentially recorded. Also, the cyberspaces were initially nothing more than two-dimensional graphic representations. Recently, however, a three-dimensional chatting system has appeared in which participants have conversations a three-dimensional virtual space, providing a place of communication in a shared virtual society abounding with realistic touches built and provided on the Internet.
A three-dimensional shared virtual space is described in VRML and can be downloaded from a WWW server through the Internet for example. Each participant who logs in a shared virtual space is allocated with an avatar, which is equivalent to the alter ego of the user. The avatar is a type of an application object generated by an application program. Information (for example, current position, attire, name, and gender) about each avatar in a shared virtual space is shared among the log-in users, so that the avatars of own and other users appear on the monitor screen of each user. Each user can make his avatar search the shared virtual space as if the user himself searched the real world. Remarks inputted by a user through the keyboard are displayed on the monitor screen of all participating users in the form of a speech balloon popping up from the avatar of the remarking user.
Three-dimensional shared virtual worlds can visually attract more users than old-fashioned chatting systems in which remarks made by users are only displayed in text in a time series manner. Each three-dimensional shared virtual space also allows users to check realtime the reactions of others through three-dimensional graphical representation, thereby making conversations livelier. The participating users can share virtual or pseudo experiences such as events that take place in the shared virtual world. In addition, the participating users can execute game-like interactive operations such as searching for other avatars or escaping from them in the three-dimensional space. Further, introduction of time mechanisms for providing day and night and seasons for example and other changes simulating the real world enhances the sense of virtual reality, thereby providing a user-friendly environment in each shared virtual space.
U.S. Pat. No. 5,956,038 (equivalent to Japanese Patent Laid-open No. Hei 9-81781) assigned to the applicant hereof for example discloses a three-dimensional virtual reality space system in which users can roam about by use of the viewpoints of their avatars in a three-dimensionally expressed shared virtual space. This shared virtual space can be described by use of a VRML description language.
Each three-dimensional shared virtual space is high computerized and therefore, as compared with a physical real world, virtual social infrastructures can be built more easily by computer processing. For example, a calling card system by which calling cards and other information are exchanged among avatars, a distribution system (for example, virtual shop, virtual currency, and virtual barter), a virtual space mailing system may be introduced (for example, Japanese Patent Laid-open No. Hei 11-203009 assigned to the applicant hereof equivalent to U.S. application for patent Ser. No. 09/227,689 discloses the introduction of calling cards in a shared virtual space.) Namely, passing a calling card to the virtual creature object bred by a user not accessing the shared virtual spaces can realize communication between users. Further, the three-dimensional shared virtual space can extend the activity radius of each avatar and expand a shared virtual space to accommodate more log-in users, or avatars.
As described, positional information and other information associated with avatars existing in a shared virtual space is shared by the log-in users, each user being capable of observing the avatars of own and other users on the monitor screen. However, distribution of the information about an expansive shared virtual space in its entirety to users is difficult or impracticable due to such physical constraints in the Internet as line bandwidth. The distance between avatars implies the degree of interest and intimacy between users and therefore the information about avatars separated far away from own avatar may be unnecessary for that user to have.
Consequently, a so-called aura algorithm scheme is employed in which, generally, only the information inside an area of interest, namely an aura, is transferred to each user, the information outside the aura being prevented from distribution. Generally, an aura is defined on the basis of the current position of an avatar. For the details of the aura algorithm, refer to, for example, Beford, S., and Fahlen, L., “A Spacial Model of Interaction in Large Virtual Environments,” Proc. Of G. DeMichelis et al. (Eds.), Third European Conference on Computer Supported Cooperative Work, Kluwer Academic Publishers, pp. 109–124, 1993.
Introducing the concept of aura into a shared virtual society can reduce the volume of data to be distributed to each user, at cost that communication with users outside that aura is disabled because the extra-aura information is not transferred to the users inside the aura.
An avatar symbolizing each user is living in a shared virtual space while almost always moving, chasing or escaping other avatars for example. Therefore, the supply of information about an avatar getting outside the aura is discontinued and, if this happens, there is no way of communicating with it.
To overcome this drawback, a virtual communications infrastructure called “mobile phone” is introduced in a shared virtual space to acquire a method of communicating with avatars outside the aura or remotely separated avatars. This method allows each avatar, regardless of inside or outside the aura, can establish communication with others by dialing their mobile phones. In the real world also, the telephone denotes a device for supporting realtime communication between remotely separated users. In having conversations by use of virtual mobile phones, an avatar need not at all bring a mate avatar into the own aura. The virtual mobile phone also allows direct communication with avatars which are missing inside the aura.
The virtual mobile phone introduced in a shared virtual space (hereafter also referred to as a virtual telephone) not only realizes one-to-one realtime communication between avatars in the same shared virtual space but also may have the basic features of the mobile phone of the real world. For example, these features include a telephone directory capability by which the names and telephone numbers are registered beforehand and only a registered name need to be selected for dialing, an incoming call rejection directory capability by which specific users are registered beforehand to reject the receipt of their calls, and a nuisance call rejection capability by which the calls from the specified users registered in the incoming call rejection directory are rejected.
Use of the virtual telephone makes it unnecessary for each avatar to remain inside its aura to establish communication with each other. Namely, use of the virtual telephone allows each user to communicate with avatars which is outside the aura or the monitor screen, thereby making it unnecessary for each user to search the immense virtual shared space for companionship with other avatars or users.
If avatars make an agreement for meeting some day in the shared virtual space, the possibility of the reunion is low unless the place and time of the meeting are set. Use of the virtual telephone eliminates this necessity for the place and time setting because the avatars equipped with the virtual telephone only need to be exist in the same shared virtual space at the same time. In addition, the virtual telephone makes it unnecessary for each user to make a direct, face-to-face contact with the avatar of another user for passing a message.
Originally, the telephone is for remote communication. Therefore, some users want to make avatar communication not only inside a single virtual space, but also with other virtual spaces and even with the real world.
For example, a user who cannot log in a chat system, namely cannot enter a shared virtual space, due to some urgent business or the like may want to talk with another avatar, namely a user who is logging in the chat system. In another example, if the avatar of another user does not appear in a shared virtual space at an appointed time, namely the user of that avatar is not logging in the chat system, the mate user may want to send a message to that log-off user.
A virtual shared space itself is constructed in a distributed computing environment such as the Internet in which many computers are networked. A gateway to another world beyond a single virtual space is obviously desired by its users.